Alloying is an effective approach to improve the catalysis performance of Pd-based catalysts for the selective hydrogenation of diolefins towards monoolefines. Herein, PdAgCu ternary nanoalloy catalysts were synthesised by a stepwise impregnation method for isoprene selective hydrogenation. The addition of a moderate amount of Ag and Cu to Pd significantly enhances the isoamylene selectivity in the isoprene hydrogenation, and decreases the non-desired over-hydrogenation. In addition, the loading molar ratio of PdAgCu with 3 : 2 : 3 as the optimal ternary nanoalloy composition maximizes the isoprene conversion (98%) and the monoolefins yield (92%). The surface structure of the catalyst was probed using H2-TPR, TEM, XRD, and XPS characterization methods, and it was confirmed that the surface Pd composition ratio between the metallic and oxidized states shows significant effects on the monoolefines yield. This work demonstrates the advantages of PdAgCu ternary nanoalloy catalysts for isoprene selective hydrogenation, which also provides guidelines for the development of other Pd-based ternary nanoalloys for diolefins selective hydrogenation.
对碳四(C4)馏分中的炔烃进行选择性催化加氢是实现混合C4资源高附加值利用的有效途径,具有显著的经济效益和社会效益.通过介绍C4炔烃的利用现状,并从选择性加氢机理入手,对国内外现有C4炔烃催化剂的研究与应用进行了概述;对非贵金属镍(Ni)、铜(Cu)催化剂与贵金属钯(Pd)催化剂的优缺点进行了对比,指出了Pd系列催化剂是目前最适合作为C4炔烃选择加氢的催化剂.针对Pd系催化剂目前存在的不足,提出了一些改进策略与今后的研究方向.分析研究表明,Pd系纳米催化剂的载体预处理、助剂改性、微观调控以及单原子催化剂的可控制备是国内C4资源充分利用的重要途径.